Fenix TK21R Military and Duty Flashlight

Product Overview

The Fenix TK21R is a robust and versatile flashlight designed for military and duty applications, offering exceptional brightness and long-range illumination. It features a powerful Luminus SFT90 LED, delivering up to 3600 lumens and a beam distance of 480 meters. The flashlight is powered by a single 21700 rechargeable Li-ion battery and includes a convenient USB Type-C charging port.

Its durable construction, advanced features like the Pulse-Frequency Transmission System (APF), and dual tactical tail switch make it a reliable tool for professionals and outdoor enthusiasts alike. The TK21R is also IP68 rated for submersion and impact resistant up to 1 meter.

Visual Description

The Fenix TK21R flashlight is depicted as a tactical torch with a sleek, durable aluminum body. Key components are highlighted in a technical diagram: the functional switch, a body clip for secure attachment, a battery replacement area, and a hidden USB Type-C charging port. A tactical switch is located at the tail end for quick activation. The diagram also illustrates the control functions: ON/OFF and Strobe modes activated via the switches.

Another visual element is a line graph showing lumen output versus runtime for different modes (Burst, High, Med, Low). The Burst mode provides the highest initial output, followed by a gradual decrease, while Low mode offers the longest runtime. A third diagram indicates the relationship between operating modes (High, Med, Low) and their corresponding beam distance and intensity (candela), demonstrating the flashlight's long-range capability.

Technical Parameters

*The Burst output is measured in total of runtime including output at reduced levels due to temperature or protection mechanism in the design.

Note: According to the ANSI/PLATO FL1 standard, the above specifications are from the results produced by Fenix through its laboratory testing using one Fenix ARB-L21-6000 battery under the temperature of 21±3°C and humidity of 50% - 80%. The true performance of this product may vary according to different working environments and the actual battery used.

Operating Instructions

On/Off

• Tap the tactical switch to turn on the light silently; release it and the light will go out.
• Fully press the tactical switch to constantly turn on the light; press again to turn it off.

Switches

• The round tail switch is the tactical switch for instant burst.
• The oval tail switch is the functional switch for output selection and instant strobe.

Output Selection

• With the light turned on, single click the functional switch to cycle through Low, Med, High, and Burst modes.

Instant Burst

• Fully press the tactical switch for 0.5 seconds to enter Burst mode and maintain this output.

Strobe Mode

• With the light turned off, tap the functional switch to enter Strobe; release it and the light will go out.
• With the light turned on, press and hold the functional switch for 0.5 seconds to enter Strobe. Tap either switch again to exit Strobe and recall the previously used output, or fully press the tactical switch to turn the light off.

Intelligent Memory Circuit

The light automatically memorizes the last selected output, excluding Strobe. When turned on again, the previously used output will be recalled.

Battery Information

Battery Specifications

Do not use an 18650, CR123A, or 16340 battery.

21700 Li-ion batteries are powerful cells designed for commercial applications and must be treated with caution and handled with care. Using low-quality batteries or mishandling batteries (such as short-circuiting or overheating) could lead to combustion and jeopardize the safety of users and property. Any adverse effects resulting from the use of low-quality batteries are not covered by any Fenix warranty or liability. Using quality batteries with circuit protection will reduce the potential for combustion or explosion.

Battery Replacement

Unscrew the light tail and insert the battery with the anode side (+) towards the light head, then screw the light tail back on.

Charging

1. Unscrew the light neck counterclockwise to reveal the charging port, then connect the USB Type-C end of the charging cable to the light.
2. The indicator will display red while charging and will turn green when fully charged.
3. Once charging is completed, be sure to unplug the charging cable and screw the light neck back to maintain the dustproof and waterproof ability.

Note:
1. When charging fails or the battery is reversely connected, the battery level indicator will flash red or remain off to remind users to check the battery.
2. The charging time of the included Fenix ARB-L21-6000 battery is about 1.5 hours from depleted to fully charged with a 9V/3A charging adapter or about 2.5 hours from depleted to fully charged with a 5V/3A charging adapter.
3. Recharge a stored light every four months to maintain the optimum performance of the battery.
4. The light cannot be operated while charging.
5. Check the battery if the battery level indicator blinks or remains off. It is strictly prohibited to charge the light while using an 18650, CR123A, or 16340 battery.
*Note: The battery level indicator only works with a Fenix ARB-L21 Series rechargeable battery.

Battery Level Indication

Each time the light is turned on, except for Strobe, the indicator (unscrew the light neck to see) will indicate the battery level and will last for 3 seconds.

• Green light on: saturated 100% - 85%
• Green light flashes: sufficient 85% - 50%
• Red light on: poor 50% - 25%
• Red light flashes: critical 25% - 1%

*Note: This only works with a Fenix ARB-L21 Series rechargeable battery.

Safety Features

Intelligent Overheat Protection

The light will accumulate a lot of heat when used at high output levels for extended periods. When the light reaches a temperature of 55°C/131°F or above, it will automatically step down a few lumens to reduce the temperature. When the temperature drops below 55°C/131°F, the light will gradually recall the preset output level.

Low-Voltage Warning

When the voltage level drops below the preset level, the flashlight is programmed to downshift to a lower brightness level until Low output is reached. When this happens in Low output, the flashlight blinks 3 times every 5 minutes to remind users to timely recharge or replace the battery.

*Note: This only works with a Fenix ARB-L21 Series rechargeable battery.

Usage and Maintenance

Disassembling the sealed head can cause damage to the light and will void the warranty.

Fenix recommends using an excellent quality battery.

If the light will not be used for an extended period, remove the battery, or the light could be damaged by electrolyte leakage. Unscrew the light tail half a turn or take out the battery to prevent accidental activation during storage or transportation.

Long-term use can result in O-ring wear. To maintain a proper water seal, replace the ring with an approved spare.

Periodic cleaning of the light and battery contacts improves the light's performance as dirty contacts may cause the lamp to flicker, shine intermittently or even fail to illuminate for the following reasons:

• A: Poor battery level. Solution: Recharge or replace the battery.
• B: The contact or contact point of the battery or light is dirty. Solution: Clean the contact points with a cotton swab soaked in rubbing alcohol.

If the above methods don't work, please contact the distributor.

Included Items

• Fenix TK21R flashlight
• ARB-L21-6000 battery
• USB Type-C charging cable
• Holster
• Lanyard
• 2 x Spare O-rings
• User manual
• Warranty card

Company Information

FENIXLIGHT LIMITED

Tel: +86-755-29631163/83/93

Fax: +86-755-29631181

E-mail: info@fenixlight.com

Web: www.fenixlight.com

Address: 2F/3F, West of Building A, Xinghong Technology Park, 111 Shuiku Road, Fenghuanggang Community, Xixiang Street, Bao'an District, Shenzhen City, Guangdong Province, China

Social Media: Follow Fenix on Facebook for more information.

Certifications: FC, CE

Product Identifier: 61.149.221.147-A0-20250416

Warnings

Do NOT place this light in the reach of children!

Do NOT shine the light directly into the eyes of anyone!

Do NOT place light head near flammable objects, high temperatures can cause objects to overheat and become flammable/ignite!

Do NOT use the light in inappropriate ways such as holding the unit in your mouth, doing so could cause serious personal injury or death if the light or internal battery fails!

This light will accumulate a significant amount of heat while operating, resulting in a high temperature of the light shell. Pay close attention to avoid burns.

Remove the battery to prevent accidental activation when the light is placed in a closed and flammable environment such as pockets and backpacks!

The LED of this light is not replaceable; so the whole light should be replaced when the LED reaches the end of its lifespan.